干旱气象
榦旱氣象
간한기상
GANSU METEOROLOGY
2014年
2期
175-183
,共9页
广义位温%西北地区%夏季降水
廣義位溫%西北地區%夏季降水
엄의위온%서북지구%하계강수
generalized potential temperature%Northwest China%summer precipitation
利用1958～2012年JRA55月平均再分析资料和我国西北地区33站降水资料，通过EOF、相关、合成、SVD等统计方法，分析了500 hPa广义位温场与我国西北地区夏季降水的关系。结果表明：夏季500 hPa关键区（40°E～80°E，30°N～60°N）广义位温场与我国西北地区降水关系最为密切，当里海、咸海、贝加尔湖以北地区对流层中层偏暖湿，中亚南部偏冷干时，我国西北地区西部降水偏多，而东部降水偏少。尤其是在新疆南部及甘肃北部降水偏多更为显著，而甘肃南部降水偏少则最为明显；反之亦然。前期2月500 hPa广义位温场自赤道阿拉伯海沿南亚印度北部、中国西北至北亚，呈西南东北向的“＋"#"”分布时，随后夏季西北地区降水西部多、东部少。并且，夏季关键区对流层中层广义位温场的异常变化，对应着不同的大气环流场异常，而这种环流形势则进一步影响我国西北地区东西部的降水异常。
利用1958～2012年JRA55月平均再分析資料和我國西北地區33站降水資料，通過EOF、相關、閤成、SVD等統計方法，分析瞭500 hPa廣義位溫場與我國西北地區夏季降水的關繫。結果錶明：夏季500 hPa關鍵區（40°E～80°E，30°N～60°N）廣義位溫場與我國西北地區降水關繫最為密切，噹裏海、鹹海、貝加爾湖以北地區對流層中層偏暖濕，中亞南部偏冷榦時，我國西北地區西部降水偏多，而東部降水偏少。尤其是在新疆南部及甘肅北部降水偏多更為顯著，而甘肅南部降水偏少則最為明顯；反之亦然。前期2月500 hPa廣義位溫場自赤道阿拉伯海沿南亞印度北部、中國西北至北亞，呈西南東北嚮的“＋"#"”分佈時，隨後夏季西北地區降水西部多、東部少。併且，夏季關鍵區對流層中層廣義位溫場的異常變化，對應著不同的大氣環流場異常，而這種環流形勢則進一步影響我國西北地區東西部的降水異常。
이용1958～2012년JRA55월평균재분석자료화아국서북지구33참강수자료，통과EOF、상관、합성、SVD등통계방법，분석료500 hPa엄의위온장여아국서북지구하계강수적관계。결과표명：하계500 hPa관건구（40°E～80°E，30°N～60°N）엄의위온장여아국서북지구강수관계최위밀절，당리해、함해、패가이호이북지구대류층중층편난습，중아남부편랭간시，아국서북지구서부강수편다，이동부강수편소。우기시재신강남부급감숙북부강수편다경위현저，이감숙남부강수편소칙최위명현；반지역연。전기2월500 hPa엄의위온장자적도아랍백해연남아인도북부、중국서북지북아，정서남동북향적“＋"#"”분포시，수후하계서북지구강수서부다、동부소。병차，하계관건구대류층중층엄의위온장적이상변화，대응착불동적대기배류장이상，이저충배류형세칙진일보영향아국서북지구동서부적강수이상。
Based on the JRA55 monthly averaged reanalysis data during1958-2012 and monthly precipitation data from 33 stations in Northwest China,the relationships between 500 hPa generalized potential temperature and summer precipitation over there were dis-cussed by using the EOF,correlation,composite and SVD technique. Results show that the 500 hPa generalized potential temperature over the key areas (40°E-80°E,30°N-60°N)in summer was closely related with the contemporaneous precipitation in Northwest China. When the north areas of Caspian Sea,Aral Sea and Lake Baikal were warmer and wetter,and Southern Central Asia was colder and drier,the precipitation increased in western region and decreased in eastern region of Northwest China,especially in southern Xin-jiang and northern Gansu the increase of precipitation was the most significant,while in southern Gansu the decrease of precipitation was the most obvious,and vice versa. When the 500 hPa generalized potential temperature in February presented“+"#"”distri-bution from southwest to northeast along the Arabian sea,northern India,northwest China to north Asia,the following summer precipi-tation in western region increased and decreased in eastern region of Northwest China. Furthermore,anomalous variations of the gener-alized potential temperature in the middle troposphere over the key areas corresponded to different atmospheric circulation anomalies, which can further affect the precipitation anomalies in western and eastern region of Northwest China.
